Is a woman considered sinful for abstaining from intercourse with her husband due to obsessive thoughts about ritual purity, and is one wash sufficient to remove impurity, and what should she do about water splashing back from the toilet, and how can she avoid exaggeration in istinja and repeating wudu while suffering from gas?

A piece of advice for those afflicted by obsessive doubts (waswas): The cure for waswas is to ignore it and pay no attention to it. One should not deem something impure unless with absolute certainty, a certainty so strong that one would swear by it. If you doubt the impurity of your hand, do not heed this doubt, as the default state is purity. If you are certain that something has become impure, wash only the affected area of impurity and avoid washing your entire body, as that is an act of extremism and unnecessary hardship. If impurity affects the body or clothing unknowingly, the prayer is valid, as purity is a condition only when there is knowledge and ability. It is not permissible to refuse one's spouse due to waswas; rather, one should strive against one's own self.

It is advised to enter the restroom normally, perform istinja' (cleansing after defecation/urination) without obsessive doubts, then perform ablution (wudu') only once. Perform prayer with a focused heart. There is no need to doubt the purity of visitors' shoes or anything else; the default state is purity. If the husband desires his wife, she should respond to him and perform ghusl (ritual bath) to remove the state of major impurity. She should pour water only on the area of impurity if she is certain of its presence on clothes or bedding. It is also advised to consult doctors and to diligently supplicate and seek refuge in Allah to remove this affliction.